Cam controlled multi-direction steerable handles

ABSTRACT

Disclosed herein are catheter control handles that include various cam-based mechanisms for controlling the circumferential angle and radial magnitude of flexion of an attached catheter. Control handles can comprise a housing defining a longitudinal axis extending in distal and proximal directions, a cam member that is movable axially relative to the housing and also movable rotationally about the longitudinal axis relative to the housing, at least one follower engaged with the cam member such that the at least one follower moves relative to the handle in response to the movement of the cam member, and pull wires that are coupled to the at least one follower and that extend distally out of the handle and into a steerable catheter. The at least one follower can comprise plural axial sliders, a gimbal mechanism, a ball and socket mechanism, or other mechanisms.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/311,031 filed Mar. 21, 2016, which is incorporated byreference herein it its entirety.

FIELD

The present disclosure concerns control handles for steering an attachedcatheter or other transluminal device.

BACKGROUND

Transvascular techniques have been developed for introducing andimplanting prosthetic devices, such as heart valves, into a patient'sbody using a flexible transvascular catheter in a manner that is lessinvasive than open heart surgery. Typical catheter control systems onlyallow for limited flexing of the distal end of the catheter, such as intwo orthogonal axes perpendicular to the longitudinal axis of thecatheter. For example, a conventional catheter control handle mayinclude a lever or dial coupled to a pull wire running along one side ofthe catheter, such that actuating the lever or dial causes the distaltip of the catheter to flex radially to one side of the longitudinalaxis. To cause the distal tip to flex in other directions, it istypically required to actuate additional levers/dials that are coupledto other pull wires. Thus, plural actuation devices typically have to beactuated at the same time in careful combinations or sequences togenerate a desired degree of radial flexion in a desired circumferentialdirection.

SUMMARY

Disclosed herein are catheter control handles that utilize a cam basedmechanism to provide improved steerability of an attached catheter.Utilizing a cam based mechanism for determining the circumferentialangle and radial magnitude of the catheter flexion, independently fromeach other, gives the user more direct and fine control of the flexion.Some disclosed embodiments use axially movable sliders as cam followersthat ride along a sloped cam surface for controlling the tension incatheter pull wires, while other embodiments use a ball-and-socketmechanism as a cam follower, and still other embodiments use a gimbalmechanism as a cam follower. The disclosed control handles allow forindependent control of both the magnitude of radial flexion of anattached catheter and the circumferential angle in which the radialflexion occurs, without rotation of the entire catheter inside thepatient. A clutch mechanism can also be included to fix thecircumferential flexion angle while continuing to allow adjustment ofthe radial flexion angle.

The handle can comprise a flex knob, rotation of which causes axialadjustment of the cam member. The flex knob can be fixed relative to acentral shaft that extends axially through the cam member and can berotationally engaged with the housing to allow rotation of the flex knoband central shaft relative to the housing and restrict axial motion ofthe flex knob and central shaft relative to the housing. The centralshaft can be engaged with the cam member such that rotation of the flexknob relative to the housing causes axial motion of the cam memberrelative to the housing.

The housing can further comprise a position knob fixed relative to thecam member, wherein rotation of the position knob causes rotationaladjustment of the cam member. The position knob and the flex knob can bepositioned adjacent to a distal end of the handle or adjacent to aproximal end of the handle.

The cam member can comprise a contact surface at one axial end thatinterfaces with the follower(s), and the contact surface can have aslope that varies in axial position as a function of circumferentialposition around the longitudinal axis of the handle. The slope of thecam member contact surface can vary gradually in axial position movingcircumferentially around the contact surface, such that the follower(s)move gradually distally or proximally as the cam member is rotated aboutthe longitudinal axis of the handle.

In some embodiments, each pull wire is coupled to its own slider orfollower that slides along a longitudinal groove in the handle inresponse to its contact location along a cam member that can be rotatedand translated. Rotation of the cam member causes some of the sliders tomove distally and some of the sliders to move proximally, causing achange in the direction of the flexion. Linear translation of the cammember causes all of the sliders to slide together either distally orproximally, causing a change in the degree of flexion.

In some embodiments, a ball and socket mechanism is included such thatthe socket acts as a follower and is coupled to the pull wires, whereinthe socket articulates about the ball in response to contact with a cammember. Rotation and translation of the cam member similarly causesindependent changes to the direction of the flexion and to the degree ofthe flexion.

In some embodiments, a gimbal mechanism can be included in the handle toact as a cam follower. The pull wires can be coupled to an inner platein the gimbal mechanism, and the inner gimbal plate can be actuated inmulti-dimensions relative to the housing by rotation and translation ofa cam member that is in contact with the gimbal plate. In someembodiments, pulley systems can be included in the handle to providemechanical advantage in applying tension to the pull wires. In someembodiments, rack and pinon mechanisms can be included in the handle toprovide mechanical advantage in applying tension to the pull wires andcouple the pull wires to the cam/gimbal mechanism, which can help avoidbending and damage to the pull wires.

The foregoing and other objects, features, and advantages of thedisclosed technology will become more apparent from the followingdetailed description, which proceeds with reference to the accompanyingfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary cam-controlledmulti-direction steerable control handle for performing a transvascularprocedure, such as a delivery catheter for a prosthetic heart valve,which includes plural sliders that ride along a surface of a cam andcontrol motion of a connected catheter. FIG. 21 shows the handles ofFIG. 1 coupled to a catheter.

FIG. 2 is an exploded perspective view of the control handle of FIG. 1.

FIG. 3 is a perspective view of a portion of another cam-controlledsteerable catheter control handle for a transvascular device, whichincludes a ball-and-socket cam mechanism.

FIGS. 4-6 are perspective views of an exemplary cam-controlledmulti-direction steerable catheter control handle including a gimbalmechanism.

FIG. 7 is a side view of the handle of FIG. 4.

FIG. 8 is a side cross-section view of the handle of FIG. 4

FIG. 9 is a perspective cross-section view of the handle of FIG. 4.

FIGS. 10-12 are side views showing various configurations of the handleof FIG. 4.

FIG. 13 is a perspective view of another exemplary cam-controlledmulti-direction steerable handle including a gimbal mechanism.

FIG. 14 is a side cross-section view of the handle of FIG. 13.

FIG. 15 is a side view of the handle of FIG. 13.

FIGS. 16-19 are side views showing various configurations of the handleof FIG. 13.

FIG. 20 is a schematic illustrating an alternative gimbal-based wiredrive mechanism for a catheter control handle utilizing rack and pinionmechanisms for mechanical advantage in applying tension to the pullwires.

FIG. 21 shows the control handle of FIG. 1 coupled to a flexiblecatheter, illustrating the steerability of the catheter using thecontrol handle.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate an exemplary catheter control handle 10 thatprovides cam-controlled multi-directional steerability for an attachedcatheter. A distal end 40 of the handle can be coupled to atransvascular catheter (see system 500 in FIG. 21) or other elongatedand steerable tubular device for insertion into a patient, while aproximal end 41 may include luminal access for passage of other devicesand/or fluids through the handle 10 and the attached catheter.

The handle 10 can comprise a cam member 16 having a sloped proximalsurface 46 along which sliders 22 slide. The sliders 22 are constrainedto only axial motion such that they act as cam followers. The sliders 22can be coupled to pull wires running along sides of the catheter suchthat axial motion of the sliders 22 in slots 68 applies/changes tensionon the associated pull wires. Any number of sliders and pull wires canbe included.

The handle 10 can include a first knob 42 (referred to herein as the“flex knob”) that causes axial translation of the cam 16, a second knob60 (referred to herein as the “position knob”) that causescircumferential rotation of the cam 16, and optionally a third knob 34(referred to herein as the “clutch knob”) that serves as a clutch orbreak to lock in the rotational position of the cam 16 selected by thesecond knob 60 while allowing adjustment to the axial position of thecam via the flex knob 42.

By rotating the flex knob 42, the user can cause the cam 16 to moveaxially relative to the rest of the handle, which causes all of thesliders 22 to move axially a corresponding distance, which in turncauses all of the pull wires attached to the sliders to increase ordecrease in tension together, resulting in a change in the magnitude ofthe radial flexion of the distal tip of the attached catheter (butdoesn't necessarily change to circumferential angle of the flexedcatheter tip).

By rotating the position knob 60, the user can cause the cam 16 and itssloped end surface 46 to rotate around the central axis of the handle,causing one or more of the sliders 22 to move distally in the slots 68and one or more other sliders to move proximally in the slots 68,depending on which part of the sloped end surface 46 is in contact witheach slider 22. This can cause increased tension in one or more pullwires and simultaneous reduction in tension one or more other pullwires, which results in the flexed distal tip of the attached catheterpivoting about its central axis and changing the circumferential anglein which it is radially flexed (without rotating the whole catheterinside the patient.

Accordingly, each of the flex knob 42 and the position knob 60 canindividually adjust all of the sliders 22 and associated pull wires withadjustment of a single knob, and each of the knobs 42 and 60 cangenerate a very different, yet complimentary, resultant adjustment tothe distal tip of the catheter.

In one exemplary method, starting with the attached catheter having astraightened distal tip, the user can first rotate the flex knob 42 asufficient amount to cause the distal tip of the catheter to flexradially to a desired angle from the longitudinal axis of thestraightened position (e.g., to flexion angle of 30 degrees fromstraight). This flexion can be purely radial, with no circumferentialmotion (e.g., the radial flexion can occur while the distal tip is at afixed circumferential angle of zero degrees). Then, the user can rotatethe position knob 60 to cause the distal tip of the catheter togradually change the circumferential angle in which it is radiallyflexed. For example, rotating the position knob 60 one direction cancause clockwise change in the circumferential angle of the distal tip,while rotating the position knob in the opposite direction can causecounter-clockwise change in the circumferential angle. This change inthe circumferential angle can be caused while maintaining the degree ofradial flexion of the distal tip. Furthermore, when the position knob 60is used to change the circumferential angle of the distal tip flexion,the catheter itself does not need to be rotated inside the patient.Instead, the distal tip of the catheter is simply flexed in a differentcircumferential direction from straight while the rest of the cathetercan remain stationary.

In another exemplary method, starting with the attached catheter havinga straightened distal tip, the user can first rotate the position knob60 to rotate the cam 16 to a selected circumferential positioncorresponding with the desired flexion direction of the distal tip ofthe catheter (e.g., 270 degrees clockwise from a designated referencepoint). Then, the user can rotate the flex knob 42 a sufficient amountto cause the distal tip of the catheter to flex radially in the desireddirection to a desired angle from the longitudinal axis of thestraightened position (e.g., to flexion angle of 30 degrees fromstraight). This flexion can be purely radial, with no circumferentialmotion (e.g., the radial flexion from zero to 30 degrees can occur whilethe distal tip is at the fixed circumferential angle of 270 degrees).Furthermore, after the desired circumferential angle is set with theposition knob 60, the clutch knob 34 can be engaged to freeze thecircumferential angle while permitting radial flexion of the distal tipusing the flex knob 42.

As shown in FIGS. 1 and 2, the handle 10 includes a distal nose cone 12,a flex component 14 that can include the flex knob 41 and a threadedbody 44, the cam 16, pins 18, a stationary slider guide 20 includingdistal body 48 and a proximal body 50 with slider grooves 52, thesliders 22 each having an outwardly projecting pin 54, a back plug 25with a disk portion 56 and a proximal shaft 58, a positioning component26 including the positioning knob 60 and a proximal cylinder 64 withslots/grooves 68, a washer 28, spacers 30, an outer sheath 32, theclutch knob 34, proximal gasket 36, and proximal end cap 38 forming theproximal end 41. Various retainers/fasteners (e.g., retaining rings 70)can also be included. As shown in FIG. 1, the sliders 22 can slideaxially along the grooves 52 while their slider pins 54 project out tothe radial dimension of the cam 16. The cam 16 is positioned between theproximal body 50 and the proximal cylinder 64, such that the slider pins54 contact the sloped proximal end surface 46 of the cam 16. The cam 16can be coupled to the positioning component 26 such that rotation of thepositioning knob 60 cause the cam to rotate, while at the same time theproximal cylinder 64 allows the cam to slide axially between thestationary slider guide 20 and the positioning component 26.

The threaded body 44 of the flex component 14 can be positioned aroundthe distal body 48 of the stationary slider guide 20 and also engaged tothe cam 16 such that rotation of the flex component 14 drives the camaxially relative to the stationary slider guide 20 and the cylinder 64of the positioning component 26.

The clutch knob 34 can have an engaged position and a disengagedposition. When in the engaged position, the position knob 60 can belocked such that the circumferential angle of distal tip is fixed, whileallowing the flex knob 42 to drive the cam 16 axially and change themagnitude of radial flexion of distal tip. When the clutch knob 34 is inthe disengaged position, both the flex knob and the position knob arefunctional.

Each of the sliders 22 can be attached to one end of a pull wire thatruns distally through the handle 10, out the distal end 40, and alongthe attached catheter. The handle 10 can include 2, 3, 4, or moresliders and associated pull wires. Four sliders 22 are included in theillustrated embodiment, each spaced about 90 degrees apart from eachother circumferentially.

The sloped proximal end surface 46 of the cam 16 can be configured toprovide a desired balance between fine control of the flexion angles anda minimal amount of knob rotation that is necessary to adjust theflexion angles. For example, a steeper slope on the cam results is morechange in radial flexion per degree of rotation of the flex knob, whilea less sloped cam surface provide more fine control of the exact angleof flexion.

The sloped end surface 46 comprises a slider contact surface having aslope that varies in axial position as a function of circumferentialposition around the longitudinal axis of the handle. The slope of thecontact surface can vary gradually in axial position movingcircumferentially around the contact surface, such that the sliders movegradually proximally and distally as the cam is rotated about thelongitudinal axis of the handle. The contact surface can comprises anannular surface that extends circumferentially around a central shaftand/or central lumen of the handle. The contact surface can comprise anyplanar or non-planar profile, such as a planar surface that defines anoblique plane that is not parallel or perpendicular to the longitudinalaxis of the handle.

The flex knob 42 and the position knob 60 can be rotated at the sametime or individually. For example, in an exemplary method, the two knobscan be rotated at the same time (in either the same rotational directionor in opposite rotational directions). Simultaneous rotation of the twoknobs can cause the cam 16 to slide axially and rotate circumferentiallyat the same time, which causes the distal tip of the catheter to bothchange its degree of radial flexion and change the circumferentialdirection of the flexion.

The handle 10 can be manually operated with one hand or with two hands.Since the knobs 42 and 60 are close to each other, the user can operateboth knobs with one hand while holding the handle 10.

The use of a cam feature in the disclosed control handles can provide aninfinite degree of choice in selecting a desired flexion position of thedistal tip of an attached catheter (see FIG. 21), as the cam feature canprovide an analog adjustment mechanism. Furthermore, with regard to thecontrol handle 10, an increased number of sliders and/or an increasednumber of different pull wires that are included and coupled to thesliders 22 can improve the smoothness of the analog control systemsdescribed herein.

With reference to FIG. 21, rotating the flex knob 42 causes the catheter520 to flex in a radial direction, such as any of the four exemplaryradial direction R1, R2, R3, R4 labeled in FIG. 21, or direction inbetween the labeled directions. When the cam member 16 is in its distalposition, the catheter can be relaxed and/or not flexed, such as isshown by the position P1 in FIG. 21. When the cam member is drivenproximally, moving the slides proximally with it, the pull wires aretensioned, causing the catheter to flex radially, such as to any of theflexed positions labeled P1, P2, P3, P4 in FIG. 21. The circumferentialangle in which the catheter flexes is determined by the position of theposition knob 42. The rotational position of the position knob cancorrespond to circumferential motion of the flexed catheter in thedirections labeled C. For example, if the catheter is currently in theflexed position P4, rotation of the position knob 60 degrees (while theflex knob is stationary) can move the catheter to position P3 or toposition P5 along the dashed line (while the catheter does not rotateabout its central longitudinal axis). If the catheter is currently inthe unflexed position P1, rotation of the position knob may not causeany motion of the catheter (not even rotation of the catheter about itscentral longitudinal axis), but can determine in which radial direction(e.g., R1, R2, R3, R4) the catheter will flex when the flex knob issubsequently rotated. By adjusting the flex knob 42 and the positionknob 60 in combination (simultaneously or one at a time), the catheter520 can be steered to any flex position within the dashed circle in FIG.21 (assuming the dashed circle represents the maximum degree offlexion), without rotating the catheter about its central longitudinalaxis within a patient's body (rotation of the catheter within a vessel,for example, can damage the inner lining of the vessel).

FIG. 3 illustrates another exemplary control handle 100 comprising acentral tubular shaft 102, 103 having a distal end 104 and proximal end106, a distal component 110 fixed to the shaft, a socket 112, and a ball120 mounted on the shaft inside the socket. The distal component 110includes a flex knob 114 and a cam body 116 with a proximally extendingcam finger 118 that contacts a distal engagement surface 124 of thesocket 112. The rotational orientation of the socket 112 relative to thecam finger 118 (e.g., selected be rotating the socket) determines whichwhat the socket tilts relative to the ball 120, which determines thecircumferential flexion angle of the distal tip of the catheter. Theaxial position of the cam finger 118 relative to the socket 112 (e.g.,selected by rotation of the flex knob 114) determines the magnitude ofaxial flexion of the distal tip of the catheter. The socket 112 notches126 and grooves 128, 130 around its outer perimeter. Plural guidewiresare coupled to the socket around its perimeter and run distally into thecatheter.

FIGS. 4-12 illustrate another exemplary control handle 200 that includesa cam member that interfaces with a gimbal mechanism to control tensionon several different pull wires. The handle 200 comprises a housing 210having a distal end 212 and a proximal inner cavity 214 that contains agimbal mechanism comprising an outer gimbal ring 216 and an inner gimbalplate 218. The ring 216 is pivotably mounted relative to the housing 210at pivot joints 250 so that the ring can rotate relative to the housingabout a ring axis passing through joints 250 perpendicular to thelongitudinal axis of the handle. The plate 218 is pivotably mountedrelative to the ring 216 at pivot points 252 such that the plate canrotate relative to the ring about a plate axis passing through joints252 perpendicular to the ring axis. The plate axis and ring axis arerotationally fixed about the housing axis, but the plate can pivotmultidirectionally relative to the housing as the ring pivots relativeto the housing through joints 250 and as the plate pivots relative tothe ring through joints 252.

The gimbal plate 218 includes wire engagements 220 for each pull wire222 of the handle. There maybe two, three, four, five, six, seven,eight, or more pull wires 222. Four pull wires 222 are illustrated as anexample. Each wire 222 passes through passageways 226 in the handle andextends out from distal openings 228 into an attached catheter or othersimilar steerable device. FIG. 21 shows an exemplary catheter. The wires222 can optionally loop around respective wire engagements 220 in thegimbal plate 218, as illustrated, such that end portions 224 of thewires extend back distally to fixed attachment points on the housing. Insuch embodiments, the wire engagements 220 can comprise a rounded peg,pulley, or other feature to facilitate the wires sliding around the wireengagement with minimal friction and kinking as the plate articulates.This arrangement can provide mechanical advantage, effectively halvingthe pulling force applied to the wires while causing the distal ends ofthe wires in the catheter to move at twice the rate that the wireengagements in the plate move. In alternative embodiments, the wires canterminate at the wire engagements 220 in the gimbal plate without anymechanical advantage, which can avoid bending the wires.

The handle 200 includes a central shaft 230 that has a distal end 232coupled to the housing 210, an intermediate portion that passes throughan opening 219 in the gimbal plate 218 and passing through cam member234, and a proximal portion that is fixedly coupled to a proximal flexknob 240. The distal end 232 is coupled to the housing via a rotationalbearing that allows rotation of the shaft 230 and knob 240 relative tothe housing and gimbal mechanism, but prevents longitudinal motion ofthe shaft 230 and knob 240 relative to the housing and gimbal mechanism.Although not shown, the central shaft 230 and flex knob 240 can includea central lumen extending through their entire length. The housing 210can also include a central lumen that extends from the distal end of theshaft 230 to the distal end 212 of the handle. Combined, the centrallumens of the handle 200 can provide access for other devices and/orfluids to be passed into and out of a patient through the handle andthrough a connecting lumen in an attached catheter.

The handle 200 also includes a position knob 242 with indicator nub 242that is fixedly coupled to the cam member 234 and positioned around thecentral shaft 230 distal to the flex knob 240. The cam member 234 and/orposition knob 242 can be threadedly or helically engaged to the outersurface of the central shaft 230. As illustrated in FIG. 7, when theflex knob 240 and central shaft 230 are rotated (arrow 1) relative tothe position knob 242 and cam member 234 (e.g., by holding the positionknob stationary relative to the housing 210 and turning the flex knob),the position knob and cam member are driven distally (arrow 2) orproximally relative to the housing and gimbal mechanism, causing thegimbal plate to pivot (arrow 3) and change tension on all the pullwires.

By using the flex knob 240 to drive the cam member distally orproximally, the magnitude of the flexion of the catheter is adjusted.Distal motion of the cam causes the gimbal plate to tilt more, causingincreased magnitude of flexion, and proximal motion of the cam memberallows the gimbal plate to return closer to its natural positionperpendicular to the longitudinal axis of the handle, reducing theflexion of the catheter. With reference to lower portion of FIG. 21,rotating the flex knob 240 causes the catheter to flex in the radialdirections, such the four exemplary radial direction R1, R2, R3, R4labeled in FIG. 21. When the cam member is in a proximal position,allowing the gimbal plate to be in its upright natural position, thecatheter can be relaxed and/or not flexed, such as is shown by theposition P1 in FIG. 21. When the cam member is driven distally, pivotingthe gimbal plate, pull wires on one side are tensioned, causing thecatheter to flex radially, such as to any of the flexed positionslabeled P1, P2, P3, P4 in FIG. 21. The circumferential angle in whichthe catheter flexes is determined by the position of the position knob244.

The sloped end surface of the cam member 234 comprises a gimbal platecontact surface having a slope that varies in axial position as afunction of circumferential position around the longitudinal axis of thehandle. The slope of the contact surface can vary gradually in axialposition moving circumferentially around the contact surface, such thatthe gimbal plate 218 articulates gradually as the cam is rotated aboutthe longitudinal axis of the handle. In some embodiments, only the endof the cam member 234 contacts the gimbal plate, and the same end partof the cam member remains in contact with the gimbal plate through therotational range of motion of the cam member, making the exact shape ofthe sloped contact surface of the cam member less significant. However,in some embodiments, the contact surface can comprises an annularsurface that extends circumferentially around the central shaft and/or acentral lumen of the handle, and the contact surface can comprise anyplanar or non-planar profile, such as a planar surface that defines anoblique plane that is not parallel or perpendicular to the longitudinalaxis of the handle.

In the illustrated example, the cam member 234 has a generallycylindrical radial outer surface and a sloped planar distal surface,forming an ovoid or elliptical distal surface that contacts the gimbalplate 218. In the illustrated example, the outer surface of the cammember is cylindrical and the distal surface of the cam member isplanar, forming an elliptical perimeter of the distal surface, but inalternative embodiments the cam member can include non-cylindrical outersurfaces and/or non-planar distal surfaces, resulting in non-ellipticalshapes of the distal surface. In addition, the radius of the cylindricalouter surface and/or the slope of the distal surface can be varied toadjust the profile of the distal surface. For example, a steeper or lesssteep slope at the distal end of the cam member can provide a greater orlesser magnitude of motion to the gimbal plate and thus greater or lessrange of motion to the pull wires.

FIGS. 10-12 illustrate rotation of the position knob 242 to change thecircumferential angle at which the catheter radially flexes. Therotational position of the position knob 242 can be visually and/ortactilely indicated by the nub 244 or other indicator. The position knob242 and the attached cam member 234 can be rotated 360 degrees relativeto the gimbal mechanism about the central shaft. The rotational positionof the position knob determines where the distal edge of the cam membercontacts the gimbal plate, and thus the direction in which the gimbalplate tilts when the flex knob is used to drive the cam member into thegimbal plate.

The gimbal ring 216 and gimbal plate 218 work together to allow theplate to tilt in any direction, and thus flex the catheter in any radialdirection. In FIG. 10, the ring 216 is stationary and the plate 218tilts about the plate axis, pulling on wire A and relaxing wire B. Thiscauses the catheter to flex in the direction of the wire A. In FIG. 11,the ring 218 rotates about the ring axis and the plate 216 rotates aboutthe plate axis, pulling both wires A and C, and relaxing wires B and D.This causes the catheter to flex in a direction between wires A and C.In FIG. 12, the plate 218 is stationary relative to the ring 216, andthe ring and plate rotate in unison about the ring axis, pulling on wireC and relaxing wire D. This causes the catheter to flex in the directionof the wire C.

With reference to the lower portion of FIG. 21, the rotational positionof the position knob can correspond to circumferential motion of theflexed catheter in the directions labeled C. For example, if thecatheter is currently in the flexed position P4, rotation of theposition knob 90 degrees (while the flex knob is stationary relative tothe position knob) can move the catheter to position P3 or to positionP5 along the dashed line (while the catheter does not rotate about itscentral longitudinal axis). If the catheter is currently in the unflexedposition P1, rotation of the position knob may not cause any motion ofthe catheter (not even rotation of the catheter about its centrallongitudinal axis), but can determine in which radial direction (e.g.,R1, R2, R3, R4) the catheter will flex when the flex knob issubsequently rotated.

By adjusting the flex knob and the position knob in combination(simultaneously or one at a time), the catheter can be steered to anyflex position within the dashed circle in FIG. 21 (assuming the dashedcircle represents the maximum degree of flexion), without rotating thecatheter about its central longitudinal axis within a patient's body(rotation of the catheter within a vessel, for example, can damage theinner lining of the vessel).

In some embodiments, the gimbal plate can have a non-planar contactsurface, with bump(s) and/or valley(s) which vary in heightcircumferentially and/or radially on the gimbal plate. These cancompensate for any discretization effect of not using an infinite numberof pull wires around the perimeter of the plate. For example, when thecam member pushes on the gimbal plate between two wires, it may need alittle extra pull on the pull wires in order to get the same amount offlex at the distal end of the catheter. These bumps or valleys canachieve that extra pull by tilting the plate a little more or less atcertain circumferential and radial cam contact locations. For example,if a completely planar gimbal plate is used, a slight unflexing mayoccur when the position knob is such that the flex direction is betweentwo of the pull wires. Including a gradual bump on the gimbal plate inthe location between the pull wire engagements (as just one example) cancompensate for that expected unflexing by tilting the gimbal plate alittle more when the cam contacts that bump, thereby providing theadditional pull wire motion needed to maintain a constant flexionmagnitude in a direction between two pull wires.

FIGS. 13-19 illustrate another exemplary control handle 300 thatincludes a cam member that interfaces with a gimbal mechanism to controltension on several different pull wires. The control handle 300functions in a similar manner to the control handle 200, with the majordifference being the catheter is connected to the opposite longitudinalend of the handle and the pull wires double back and extend out from theopposite longitudinal end of the handle, flipping what is the distaldirection and what is the proximal direction compared to the handle 200.

The handle 300 comprises a housing 310 forming a proximal end 314, andthe handle has a distal end 312 at or near flex knob 322. The flex knob322 is axially fixed relative to the central shaft 320, and a positionknob 324 is positioned around and/or within the flex knob in a threadedengagement or helical interface such that rotation of the flex knobdrives the position knob and affixed cam member 326 axially relative tothe gimbal mechanism inside the housing. The gimbal mechanism includes agimbal ring 316 pivotably mounted inside the housing about a ring axisand a gimbal plate 318 pivotably mounted inside the ring via pivotsalong a plate axis perpendicular to the ring axis, like with the handle200. The handle 300 also includes a wire guide plate 330 mounted insidethe housing 310 proximal to the gimbal mechanism.

Each pull wire in the handle 300 has a free end 340 fixed to the wireguide plate 330, a first portion extending from the free end 340distally to the gimbal plate 318 and around pulleys or other guides 342in the gimbal plate, a second portion that extends back proximally fromthe gimbal plate to secondary pulleys or guides 344 in the wire guideplate 330, then around the pulleys or guides 344 to third portions thatextend distally through the central shaft 320 along the length of thehandle and out through the distal end 312 of the handle into cathetercoupled to the handle.

FIG. 15 illustrates how rotating the flex knob 322 (arrow 1) causes thecam member 326 to move axially (arrow 2), and cause the distal edge ofthe cam member to tilt the gimbal plate 318 and/or ring 316 (arrow 3),which adjusts the magnitude of flexion in the attached catheter.

FIG. 16 shows the handle 300 with the gimbal ring 316 and plate 318 inthe relaxed position when the cam member is not tilting them. In thisstate, the attached catheter can be in the relaxed, non-flexed neutralposition. FIG. 17 shows the cam member 326 advanced proximally, tiltingthe gimbal plate 318 while the gimbal ring 316 remains stationary. Thiscauses flexion of the attached catheter in a selected radial direction.FIG. 18 shows the cam member 326 has been rotated a few degrees fromFIG. 17, such that both the gimbal plate and ring are pivoted. Thiscauses the attached catheter to be flexed about the same magnitude butin a correspondingly different radial direction compared to FIG. 17. InFIG. 19, the cam member is rotated about 90 degrees from FIG. 17, suchthat the gimbal ring is pivoted relative to the housing 310, but thegimbal plate is not pivoted relative to the gimbal ring. In thisposition, the attached catheter is flexed about the same radial amountas in FIGS. 17 and 18, but it is flexed in a direction that is about 90degrees from the direction corresponding the position of FIG. 17.

As the gimbal plate 318 moves relative to the wire guide plate 330, thepull wires articulate around the wire guides 342 and 344 in the twoplates, providing a mechanical advantage that magnifies the relativesmall motions of the cam member and gimbal plate to provide the desiredflexion in the catheter. Like with the handle 200, the mechanism systemthat couples the knobs 322 and 324 to the pull wires can be configuredand/or calibrated to provide the desired balance of fine control andrange of motion of catheter flexion. The gimbal mechanism also providesan analog, full 360 degree range of adjustability for the catheterflexion, without needing to rotate the catheter inside the patient.

FIG. 20 is a schematic diagram that illustrates an alternative handlesystem 400 for coupling a gimbal mechanism to pull wires without loopingor curling the pull wires. The system 400 includes a housing 410 with agimbal ring 412 and gimbal plate 414 mounted inside the housing, fixedrack gears 416 mounted in fixed relationship to the housing, moving rackgears 422 opposing each fixed rack gear 416 and coupled to the pullwires 424, rolling pinon gears 418 engaged between the fixed and movingrack gears, and rigid connector members 420 coupled from the gimbalplate 414 to the center of each pinon gear 418. A cam member (not shown)causes motion of the gimbal mechanism, which pulls and pushes on therigid connector members 420, causing the pinon gears 418 to rollcorrespondingly along the fixed rack gears 416. For each unit ofdistance the pinon gears 418 roll, the moving rack gears 422 move in thesame direction but twice as far, creating mechanical advantage thatmagnifies the motion of the cam member into greater motion of the pullwires, but without pulleys or other devices that require the pull wiresto be curled or bent around sharp angles, which can damage the wiresover time.

It should be understood that the disclosed embodiments can be adapted todeliver and implant prosthetic devices in any of the native annuluses ofthe heart (e.g., the pulmonary, mitral, and tricuspid annuluses), andcan be used with any of various approaches (e.g., retrograde, antegrade,transseptal, transventricular, transatrial, etc.). The disclosedembodiments can also be used to implant prostheses in other lumens ofthe body. Further, in addition to prosthetic valves, the deliveryassembly embodiments described herein can be adapted to deliver andimplant various other prosthetic devices such as stents and/or otherprosthetic repair devices. In other embodiments, the disclosed devicescan be used to perform various other transvascular surgical proceduresother that implanting a prosthetic device.

For purposes of this description, certain aspects, advantages, and novelfeatures of the embodiments of this disclosure are described herein. Thedisclosed methods, apparatus, and systems should not be construed asbeing limiting in any way. Instead, the present disclosure is directedtoward all novel and nonobvious features and aspects of the variousdisclosed embodiments, alone and in various combinations andsub-combinations with one another. The methods, apparatus, and systemsare not limited to any specific aspect or feature or combinationthereof, nor do the disclosed embodiments require that any one or morespecific advantages be present or problems be solved.

Although the operations of some of the disclosed embodiments aredescribed in a particular, sequential order for convenient presentation,it should be understood that this manner of description encompassesrearrangement, unless a particular ordering is required by specificlanguage set forth below. For example, operations described sequentiallymay in some cases be rearranged or performed concurrently. Moreover, forthe sake of simplicity, the attached figures may not show the variousways in which the disclosed methods can be used in conjunction withother methods. Additionally, the description sometimes uses terms like“provide” or “achieve” to describe the disclosed methods. These termsare high-level abstractions of the actual operations that are performed.The actual operations that correspond to these terms may vary dependingon the particular implementation and are readily discernible by one ofordinary skill in the art.

As used in this application and in the claims, the singular forms “a,”“an,” and “the” include the plural forms unless the context clearlydictates otherwise. Additionally, the term “includes” means “comprises.”Further, the term “coupled” generally means physically, electrically,magnetically, and/or chemically coupled or linked and does not excludethe presence of intermediate elements between the coupled or associateditems absent specific contrary language.

As used herein, the term “proximal” refers to a position, direction, orportion of a device that is closer to the user/operator of the deviceand further away from an end or destination of the device within apatient's body (e.g., the heart). As used herein, the term “distal”refers to a position, direction, or portion of a device that is furtheraway from the user/operator of the device and closer to the end ordestination of the device within a patient's body. Thus, for example,proximal motion of a catheter is motion of the catheter out of the bodyand/or toward the operator (e.g., retraction of the catheter out of thepatient's body), while distal motion of the catheter is motion of thecatheter away from the operator and further into the body (e.g.,insertion of the catheter into the body toward the heart). The terms“longitudinal” and “axial” refer to an axis extending in the proximaland distal directions, unless otherwise expressly defined.

As used herein, the terms “integrally formed” and “unitary construction”refer to a one-piece construction that does not include any welds,fasteners, or other means for securing separately formed pieces ofmaterial to each other.

As used herein, operations that occur “simultaneously” or “concurrently”occur generally at the same time as one another, although delays in theoccurrence of one operation relative to the other due to, for example,spacing, play or backlash between components in a mechanical linkagesuch as threads, gears, etc., are expressly within the scope of theabove terms, absent specific contrary language.

In view of the many possible embodiments to which the principles of thedisclosure may be applied, it should be recognized that the illustratedembodiments are only preferred examples and should not be taken aslimiting the scope of the disclosure. Rather, the scope of the disclosedtechnology is at least as broad as the following claims. We thereforeclaim as our invention all that comes within the scope of these claimsas well as their equivalents.

1. A control handle for steerable catheters, the handle comprising: ahousing defining a longitudinal axis extending in distal and proximaldirections; a cam member that is movable axially relative to the housingand also movable rotationally about the longitudinal axis relative tothe housing; at least one follower engaged with the cam member such thatthe at least one follower moves relative to the handle in response tomovement of the cam member relative to the housing; and pull wires thatare coupled to the at least one follower and that extend distally out ofthe handle and into a steerable catheter to effect flexion of thecatheter based on the position of the at least one follower relative tothe housing.
 2. The handle of claim 1, further comprising a flex knob,rotation of which causes axial adjustment of the cam member.
 3. Thehandle of claim 2, wherein the flex knob is fixed axially relative to acentral shaft that extends axially through the cam member and isrotationally engaged with the housing to allow rotation of the flex knobrelative to the housing and restrict axial motion of the flex knob andcentral shaft relative to the housing.
 4. The handle of claim 3, whereinthe central shaft is engaged with the cam member such that rotation ofthe flex knob relative to the housing causes axial motion of the cammember relative to the housing.
 5. The handle of claim 1, furthercomprising a position knob fixed relative to the cam member, whereinrotation of the position knob causes rotational adjustment of the cammember.
 6. The handle of claim 1, wherein the cam member comprises acontact surface at one axial end that interfaces with the at least onefollower, the contact surface having a slope that varies in axialposition as a function of circumferential position around thelongitudinal axis of the handle, and wherein the slope of the cam membercontact surface varies gradually in axial position movingcircumferentially around the contact surface, such that the at least onefollower moves gradually axially as the cam member is rotated about thelongitudinal axis of the handle.
 7. The handle of claim 6, wherein thecam member contact surface is a planar surface that defines an obliqueplane that is not parallel or perpendicular to the longitudinal axis ofthe handle.
 8. The handle of claim 1, wherein the at least one followercomprises a plurality of independently movable sliders each coupled to arespective one of the pull wires, and the sliders are constrained tomoving only axially relative to the housing.
 9. The handle of claim 8,wherein rotation of the cam member relative to the housing causes one ormore of the sliders to move proximally relative to the housing and alsosimultaneously causes one or more of the sliders to move distallyrelative to the housing, and wherein axial motion of the cam membercauses all of the sliders to move in the same axial direction.
 10. Thehandle of claim 1, wherein the at least one follower comprises a gimbalmechanism including a gimbal ring and a gimbal plate, wherein the gimbalring is pivotably coupled within the housing and the gimbal plate ispivotably coupled within the gimbal ring.
 11. The handle of claim 10,where in the pull wires are coupled to the gimbal plate, the cam memberis in contact with the gimbal plate, and the position of the cam memberdetermines an orientation of the gimbal mechanism, and the orientationof the gimbal mechanism determines axial positions of the pull wires.12. The handle of claim 11, wherein the gimbal plate comprises one ormore bumps or valleys where the cam member contacts the gimbal plate,such that the cam member's axial position relative to the gimbal plateis slightly adjusted when the cam member contacts the one or more bumpsor valleys.
 13. The handle of claim 10, wherein the pull wires arelooped around wire guides in the gimbal mechanism, or the pull wires arelooped around wire guides fixed relative to the housing proximal to thegimbal mechanism, or both.
 14. The handle of claim 1, wherein the atleast one follower comprises a ball and socket mechanism, wherein thecam member contacts a socket portion of the ball and second mechanism.15. The handle of claim 1, further comprising a rack and pinon mechanismthat transfers motion from the at least one follower to at least one ofthe pull wires.
 16. The handle of claim 1, further comprising a clutchmechanism configured to selectively fix one of the axial andcircumferential positions of the cam member while permitting motion theother of the axial and circumferential positions of the cam member. 17.The handle of claim 1, wherein handle is capable of allowing a user toindependently adjust a magnitude of radial flexion of an attachedcatheter and adjust a circumferential angle in which the radial flexionis directed.
 18. The handle of claim 17, wherein the magnitude of radialflexion of an attached catheter and the circumferential angle in whichthe radial flexion is directed can be adjusted using the handle withoutrotating the catheter about its longitudinal axis.
 19. A methodcomprising using the handle of claim 1 to steer a catheter coupled tothe handle by moving the cam member axially and/or circumferentiallyrelative to the housing, causing the at least one follower to moverelative to the housing and adjust tension in the pull wires and therebycausing changes in the flexion of the catheter based on the position ofthe at least one follower relative to the housing.
 20. An assemblycomprising the handle of claim 1 coupled to a catheter, wherein the pullwires extend along an axial length of the catheter and the handle isoperable to adjust a magnitude of radial flexion of the catheter andadjust a circumferential angle in which the radial flexion is directed.